Modelling of Climatic Thermal Actions in Hollow Concrete Box Cross-Sections

摘要

The temperature distribution in concrete structures varies as a result of fluctuations in solar radiation, air temperature, wind speed and long-wave radiation. Variations in temperature may cause longitudinal and transverse movements. If these movements are restrained, stresses and strains can be induced, which may contribute to cracking in the structure. To predict such thermal actions in a hollow concrete section, a finite element (FE) model was developed. Hourly resolution of climatic input data was used in the FE model to capture the daily temperature variations in the structure. The FE model was validated against temperature measurements performed in the hollow concrete arch of the New Svinesund Bridge located at the border between Sweden and Norway. To be able to use the developed model for future studies of other structures, an iterative method to consider the inside cavity air was also developed. The results of the simulations show that the model can capture the daily temperature variations. In addition, the proposed model shows acceptable agreement with the measurements from the bridge, and the calculated linear temperature differences for the bridge show good agreement with the design values in the Eurocode. The model is well suited for predicting temperature distributions and can be used for further studies of bridges, including those with box cross-sections, as well as for other concrete structures.